X draft of catobj

go/neo/client.go

@@ -88,7 +88,7 @@ func openClientByURL(u *url.URL) (zodb.IStorage, error) {
 		return nil, err
 	}
 
-	// identify ourselves via conn
+	// first identify ourselves via conn
 	storType, err := IdentifyMe(storLink, CLIENT)
 	if err != nil {
 		return nil, err	// XXX err ctx
@@ -98,6 +98,7 @@ func openClientByURL(u *url.URL) (zodb.IStorage, error) {
 		return nil, fmt.Errorf("%v: peer is not storage (identifies as %v)", storLink, storType)
 	}
 
+	// identification passed
 	conn, err := storLink.NewConn()
 	if err != nil {
 		return nil, err	// XXX err ctx ?

go/zodb/zodb.go

@@ -29,13 +29,13 @@ type Tid uint64  // transaction identifier
 type Oid uint64  // object identifier
 
 // XTid is "extended" transaction identifier. It defines a transaction for
-// oid lookup - either exactly by serial, or <beforeTid	XXX
+// oid lookup - either exactly by serial, or by < beforeTid.
 type XTid struct {
 	Tid
 	TidBefore bool	// XXX merge into Tid itself (high bit) ?
 }
 
-// Xid is "extended" oid = oid + serial/beforeTid, completely specifying object revision	XXX text
+// Xid is "extended" oid = oid + serial/beforeTid, completely specifying object address.
 type Xid struct {
 	XTid
 	Oid
@@ -140,7 +140,7 @@ type IStorage interface {
 
 	// LoadSerial and LoadBefore generalized into 1 Load  (see Xid for details)
 	// TODO data []byte -> something allocated from slab ?
-	Load(xid Xid) (data []byte, tid Tid, err error)
+	Load(xid Xid) (data []byte, tid Tid, err error)	// XXX -> StorageRecordInformation ?
 
 	// -> Prefetch(xid Xid) ...
 	// PrefetchBefore(oidv []Oid, beforeTid Tid) error (?)

go/zodb/zodbtools/catobj.go

+// Copyright (C) 2017  Nexedi SA and Contributors.
+//                     Kirill Smelkov <kirr@nexedi.com>
+//
+// This program is free software: you can Use, Study, Modify and Redistribute
+// it under the terms of the GNU General Public License version 3, or (at your
+// option) any later version, as published by the Free Software Foundation.
+//
+// You can also Link and Combine this program with other software covered by
+// the terms of any of the Open Source Initiative approved licenses and Convey
+// the resulting work. Corresponding source of such a combination shall include
+// the source code for all other software used.
+//
+// This program is distributed WITHOUT ANY WARRANTY; without even the implied
+// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+//
+// See COPYING file for full licensing terms.
+
+package zodbtools
+// Catobj - dump content of a database object
+
+import (
+	"flag"
+	"fmt"
+	"io"
+	"log"
+	"os"
+
+	"../../zodb"
+)
+
+// Catobj dumps content of one ZODB object	XXX text
+func Catobj(w io.Writer, stor zodb.IStorage, xid zodb.Xid) error {
+	var objInfo zodb.StorageRecordInformation
+
+	data, tid, err := stor.Load(xid)
+	if err != nil {
+		return err
+	}
+
+	// XXX hack - rework IStorage.Load to fill-in objInfo directly
+	objInfo.Oid = xid.Oid
+	objInfo.Tid = tid
+	objInfo.Data = data
+	objInfo.DataTid = tid	// XXX wrong
+
+	d := dumper{W: w}	// XXX HashOnly + raw dump
+	err = d.DumpData(&objInfo)
+	return err
+}
+
+// ----------------------------------------
+const catobjSummary = "dump content of a database object"
+
+func catobjUsage(w io.Writer) {
+	fmt.Fprintf(w,
+`Usage: zodb catobj [OPTIONS] <storage> xid...
+Dump content of a ZODB database object.
+
+<storage> is an URL (see 'zodb help zurl') of a ZODB-storage.
+xid is object address (see 'zodb help xid').
+
+Options:
+
+	-h --help       this help text.
+//	-hashonly	dump only hashes of objects without content.	XXX
+`)
+}
+
+func catobjMain(argv []string) {
+	flags := flag.FlagSet{Usage: func() { dumpUsage(os.Stderr) }}
+	flags.Init("", flag.ExitOnError)
+//	flags.BoolVar(&hashOnly, "hashonly", hashOnly, "dump only hashes of objects")
+	flags.Parse(argv[1:])
+
+	argv = flags.Args()
+	if len(argv) < 2 {
+		flags.Usage()
+		os.Exit(2)
+	}
+	storUrl := argv[0]
+
+	xidv := []zodb.Xid{}
+	for _, arg := range argv[1:] {
+		xid, err := zodb.ParseXid(arg)
+		if err != nil {
+			log.Fatal(err)	// XXX recheck
+		}
+
+		xidv = append(xidv, xid)
+	}
+
+	stor, err := zodb.OpenStorageURL(storUrl)	// TODO read-only
+	if err != nil {
+		log.Fatal(err)
+	}
+	// TODO defer stor.Close()
+
+	for _, xid := range xidv {
+		err = Catobj(os.Stdout, stor, xid)
+		if err != nil {
+			log.Fatal(err)
+		}
+	}
+}

go/zodb/zodbtools/command.go

@@ -46,6 +46,7 @@ var Commands = CommandRegistry{
 	// NOTE the order commands are listed here is the order how they will appear in help
 	// TODO analyze ?
 	// TODO cmp
-	{"dump", dumpSummary, dumpUsage, dumpMain},
 	{"info", infoSummary, infoUsage, infoMain},
+	{"dump", dumpSummary, dumpUsage, dumpMain},
+	{"catobj", catobjSummary, catobjUsage, catobjMain},
 }

go/zodb/zodbtools/dump.go

@@ -64,6 +64,7 @@ var _LF = []byte{'\n'}
 
 
 // DumpData dumps one data record
+// XXX naming -> DumpObj ?
 func (d *dumper) DumpData(datai *zodb.StorageRecordInformation) error {
 	buf := &d.buf
 	buf.Reset()
@@ -235,7 +236,6 @@ func dumpMain(argv []string) {
 	}
 	storUrl := argv[0]
 
-
 	if len(argv) > 1 {
 		tidRange = argv[1]
 	}

go/zodb/zodbtools/help.go

@@ -69,3 +69,8 @@ http://docs.pylonsproject.org/projects/zodburi/
 var HelpTopics = HelpRegistry{
 	{"zurl", "specifying database URL", helpZURL},
 }
+
+
+// TODO xid
+
+// TODO dump format